View source for ESP8266/Reflashing

=Firmware Issues=

I have had zero luck communicating with the [[ESP8266]] chip. I can't even get the LEDs on the board to light up.

The solution [http://www.xess.com/blog/esp8266-reflash/] is to reflash the firmware with the AT command binary image. This will, I guess, get the chip to accept AT commands on the serial RX/TX pins.

==Downloading AT Firmware Image==

Using this guide from Dave Vandenbout at Xess.com [http://www.xess.com/blog/esp8266-reflash/], which covers reflashing the ESP8266, I downloaded the AT Command firmware binary image, which was version 0.9.2.2.

Link to firmware binary on Google Drive (warning: may disappear at some point) is here: https://drive.google.com/file/d/0B3dUKfqzZnlwdUJUc2hkZDUyVjA/view?usp=sharing

File name of zipped-up binary image is <code>ESP8266_AT_V00180902_02_baudrate watchdog added.zip</code>

==Esptool Flashing Software==

In the Xess.com guide, Dave uses the Espressif-provided flash program, which is a Windows executable. Fortunately, I am blessed enough not to have any Windows computers, and will not touch it with a ten foot pole. I used the Python/PySerial-based esptool.py from themadinventor on Github [https://github.com/themadinventor/esptool] instead.

===Downloading===

You can download esptool from Github: https://github.com/themadinventor/esptool

===Installing===

You can install esptool manually using <code>python setup.py build && python setup.py install</code>. This will require the [[Pyserial]] library.

Alternatively, you can install it using pip: <code>pip install esptool</code>

===Using===

The basic usage of esptool is as follows:

<pre>
$ esptool.py -h
usage: esptool [-h] [--port PORT] [--baud BAUD]
               {load_ram,dump_mem,read_mem,write_mem,write_flash,run,image_info,make_image,elf2image,read_mac,chip_id,flash_id,read_flash,verify_flash,erase_flash,version}
               ...

esptool.py v1.1 - ESP8266 ROM Bootloader Utility

positional arguments:
  {load_ram,dump_mem,read_mem,write_mem,write_flash,run,image_info,make_image,elf2image,read_mac,chip_id,flash_id,read_flash,verify_flash,erase_flash,version}
                        Run esptool {command} -h for additional help
    load_ram            Download an image to RAM and execute
    dump_mem            Dump arbitrary memory to disk
    read_mem            Read arbitrary memory location
    write_mem           Read-modify-write to arbitrary memory location
    write_flash         Write a binary blob to flash
    run                 Run application code in flash
    image_info          Dump headers from an application image
    make_image          Create an application image from binary files
    elf2image           Create an application image from ELF file
    read_mac            Read MAC address from OTP ROM
    chip_id             Read Chip ID from OTP ROM
    flash_id            Read SPI flash manufacturer and device ID
    read_flash          Read SPI flash content
    verify_flash        Verify a binary blob against flash
    erase_flash         Perform Chip Erase on SPI flash
    version             Print esptool version

optional arguments:
  -h, --help            show this help message and exit
  --port PORT, -p PORT  Serial port device
  --baud BAUD, -b BAUD  Serial port baud rate used when flashing/reading
</pre>

I don't understand the difference between the memory and the flash (I think the flash is where it boots from, the memory contains the various instructions it can execute once it starts up), but we want to write an AT Commands firmware binary image to the flash on the chip.

=Flags=

{{ESP8266Flag}}